Open-end wrench having wedgy jaws and a recessed concave bight wall



Aug. 24, 1954 POOR 2,687,056

OPEN-END WRENCH HAVING WEDGY JAWS AND A RECESSED CONCAVE BIGHT WALL Filed Dec. 29, 1951 IN V EN TOR.

M1; MW

Patented Aug. 24, 1954 OFFICE OPEN-END WRENCH HAVING WEDGY JAWS AND A RECESSED CONCAVE EIGHT WALL Wilbur M. Foo'r, Shepherd, Mich, assignor to Blackhawk Mfg. 00., Milwaukee, Wis., a corporation of Wisconsin Application December 29, 1951, Serial No. 264,115

The present invention relates generally to improvements in wrenches, and relates more specifically' to improvements in the construction of wedge type open end nut and bolt manipulating wrenches.

wrenches to be readily applied to hexagonal as well as square nuts and bolt heads it has been common practice to provide a rounded bottom for each open ended socket; and in order to permit such a wrench to be conveniently manipulated in relatively inaccessible localities it has also been proposed to taper theopposite sides of the jaws and to dispose these wedge surfaces at diverse angles relative to the wrench handle. But in all of these prior open end wrenches, the rounded bottoms of the sockets between the jaws were constructed with straight line transverse generatrices which prevented the jaws from assuming maximum contact with the faces of the nuts or bolt heads unless these jaws were made of considerable length. Such lengthening of the jaws naturally made it necessary in order to provide sufiicient strength, to make the open end heads of heavy and bulky construction thus obstructing their use in cramped quarters.

It is therefore an important object of my invention to provide the socket of each head of an open ended wrench, with a transverse concavity between the opposite sides of the head, so that maximum surface contact between the jaws and the work is assured with jaws of limited length and great strength.

Another important object of this invention is to provide an improved open ended wrench head of the unitary type having maximum strength and of minimum size, adapted to be applied to work and conveniently manipulated in exceedingly cramped and relatively inaccessiblelocalities.

A further object of the invention is to provide a simple and inexpensive one-piece spanner wrench having one or more heads flexibly applicable to various types of polygonal nuts or bolt heads and associated with a conveniently mampulatable handle.

2 Claims. (01. 81-119) 1 Still another object of the present invention is to provide an attractive precision wrench of the open end jaw and intervening socket type which can be readily and accurately produced in various sizes and for diverse uses.

These andother more specific objects and advantages of my invention will be apparent from the following detailed description from which it will be noted that the gist of the present improvement is the provision of a spanner wrench head having spaced jaws provided with parallel work engaging surfaces forming an intervening open ended socket the bottom of which has a work receiving concavity disposed transversely of and between the opposite side'faces of the head.

A clear conception of the improved structure and of the construction and use of several commercial embodiments of the invention, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a perspective view of a double headed open end wrench having one embodiment of the invention incorporated therein;

Fig. 2 is an enlarged side view of one of the end heads of the wrench of Fig. 1;

Fig. 3 is a similarly enlarged central section through the wrench head of Fig. 2, taken along the line 33 of Fig. 2;

Fig. 4 is a perspective view of a double headed open end wrench having another embodiment of the invention incorporated therein;

Fig. 5 is an enlarged side View of one of the end heads of the wrench of Fig. 4;

Fig. 6 is a likewise enlarged central section through the wrench head of Fig. 5, taken along the line 6-45 of Fig. 5;

Fig. '7 is a perspective view of a modified wrench head also embodying the invention;

Fig. 8 is a central longitudinal section through the wrenchhead of Fig. '7, taken along the line 88;

Fig. 9 is a perspective view of a further modified wrench head embodying the invention;

Fig. 10 is a central-longitudinal section through the wrench head of Fig. 9, taken along the line l0lil;

Fig. 11 is a view showing the application of the wrench head of Figs. 9 and 10 to a square nut; and

Fig. 12 is a similar view showing the application of the same wrench head to the square nut in work clamping position.

While the invention has been shown and de- I scribed herein as having been applied to solid headed wrenches of the wedge or tapered type, it is not intended to unnecessarily restrict the use of the improvements to such wrenches; and it is also contemplated that specific descriptive terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawing and especially to the embodiment of the invention shown in Figs. 1 to 3 inclusive, the double headed open end wrench illustrated therein, comprises an elongated manipulating handle l2 having a spanner head I 3 formed integral with each end thereof, each head it being provided with a pair of spaced jaws I l having parallel inner work engaging surfaces It and tapered opposite outer side surfaces i6, and also being provided with an arcuately curved concavity ll disposed between the jaw surfaces 15 and extending transversely across the bottom of the open ended socket lfl'so as to connect parallel opposite outer side surfaces l9 bounding the head It. The entire structure is formed of one piece of durable metal and the jaws l4 are of approximately the same length while the opposed outer surfaces !6 are preferably disposed at an angle of approximately thirty degrees relative to each other, and approximately fifteen degrees relative to the central longitudinal plane of the handle l2 disposed midway between the surfaces H9. The surfaces l5, l6, IQ of each head l3, are preferably plane surfaces, but the surface which forms the concavity ll is arcuately curved and may be formed in any suitable manner as with the aid of a circular milling cutter revolving about an axis perpendicular to the jaw faces 15.

Referring to Figs. 4 to 6 inclusive of the drawing, the embodiment of the invention shown therein is essentially the same as that of Figs. 1 to 3, except that it has a concavity ii of slightly different construction, and the side surfaces [9 are of somewhat greater area in order to thicken and strengthen the innermost ends of the jaws M. In this modified structure, the concavity 21 which spans the space between the outer parallel surfaces [9 of each head l3 at the bottom of the open end socket 58, consists of a conical recess which may readily be formed by running a drill point into the center of the socket bottom midway between the jaw surfaces It. But in both embodiments the socket bottom may be curved laterally of the jaws Hi, and the concavities ll, 2? which extend transversely of the head surfaces It should be of considerable depth in order to properly perform their intended functions.

Referring to Figs. 7 and 8 of the drawing, the modified wrench head It shown therein is also essentially the same as in Figs. 1 to 3 inclusive, except that the concavity 31 is formed with four flat and angularly disposed bounding surfaces inclined toward the central longitudinal plane of the head i3 and toward the jaw surfaces I5, as well as being inclined inwardly relative to the opposite side surfaces [9. These concavity bounding surfaces may be formed in any suitable manner as by breaching, casting or forging, and are effectively coopera'ble with square or hexagonal nuts and bolt heads.

Referring to Figs. 9 and 10 of the drawing, the further modification of the invention shown therein, embodies a concavity 41 which is bounded by two fiat and angularly disposed surfaces which are inclined relative to each other 4 and to the head surfaces [9, but are perpendicular relative to the inner jaw surfaces l5 and span the gap between the jaws l4. These inclined surfaces of the concavity 41 may also be formed in any convenient manner as by casting, forging or broaching.

When any one of the improved wrenches illustrated has been properly constructed, the opposite end heads l3 of each wrench should be formed to cooperate with polygonal nuts or bolt heads of diiferent standard widths across flats, and the sockets it may be then applied to nuts 25 or to bolt heads with the wrench handle I 2 disposed either perpendicular to or at any desired oblique angle relative to the bolt or stud 22. In Fig. 11, a wrench of the type illustrated in Figs. 9 and 10 is shown applied to a nut 2| with the wrench handle substantially perpendicular to the stud 22; whereas in Fig. 12 the same wrench has been applied to the nut 2| at an angle of approximately fifteen degrees relative to the body 23 against which the nut 21 is being clamped.

All of the embodiments of the invention illustrated herein provide for greater contact of the jaw surfaces 25 with the flats of nuts or bolt heads while still permitting the use of jaws id of minimum length and thickness and without sacrificing strength in the jaws. The flat surfaces I9 at the inner ends of the jaws It also enable the wrench heads I3 to be inserted in limited spaces and manipulated at various angles while still maintaining maximum contact between the jaw surfaces l5 and the work. The

'concavities ll, 27 of the improved wrenches therefore enable the heads It to be constructed of relatively small and compact size without sacrificing strength or gripping or contact area with the work; and the provision of the flat parallel surfaces it on the heads l3 and which merge with the tapered jaw surfaces It further permits maximum reduction in sizes of the heads I3 without sacrificing strength in the jaws i4.

From the foregoing detailed description of the present improvement, it should be apparent that my invention in fact provides an openend wrench of minimum size and of maximum strength adapted to be readily constructed in various sizes and at moderate cost. The provision of the recess or concavity at the bottom of the open ended socket I3 and between the side surfaces iii of the heads l3 provides maximum contact area at the work engaging faces Id of the jaws Hi while maintaining maximum strength of these jaws when operating on different types of nuts 2 l, and

the provision of the parallel opposite side surfaces l9 reduces the wrench thickness to a minimum without affecting the jaw strength. In this respect the improved wrench also differs from all known prior open ended wrenches in some of which tapered outer surfaces of the jaws extended throughout the length of the heads-and thus produced more bulky assemblages which could not be readily applied and manipulated in cramped localities. The improved wrenches have proven highly satisfactory and successful in actual use, and may" be furnished with either single or multiple heads l3, and with inclined jaw surfaces l6 having various angularities from zero to approximately forty-five degrees relative to each other.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of utilizing the unitary open end wrenches herein shown and de'- scribed, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. In an open end wrench, a unitary work engaging head having a nut-engaging recess formed by spaced jaws extending from a bight portion, said jaws being provided with parallel nut-engaging confronting surfaces and with onposite side surfaces adjoining said confronting surfaces, each of said side surfaces inclining from said bight portion and converging toward free ends of said jaws so as to form an angle of approximately fifteen degrees between a common central plane of the jaws and a plane containing the respective side surface, said side surfaces merging into plane surfaces of said bight portion and the latter surfaces lying on opposite sides of and parallel to said central plane, said bight portion having a concave wall for enlarging said nutengaging recess, the concavity of said wall extending from one of said confronting surfaces to the other, and said concave wall also containing another cavity which further enlarges said nut engaging recess.

2. In an open end wrench, a unitary work engaging head having a nut-engaging recess formed by spaced jaws extending from a bight portion, said jaws being provided with parallel nut-engaging confronting surfaces and with opposite side surfaces adjoining said confronting surfaces, each of said side surfaces inclining from said bight portion and converging toward free ends of said jaws so as to form an angle of approximately fifteen degrees between a common central plane of the jaws and a plane containing the re spective side surface, said bight portion having a concave wall for enlarging said nut-engaging recess, the concavity of said wall extending from one of said confronting surfaces to the other, and said concave wall also having another unobstructed concavity midway between said confronting surfaces which further enlarges and increases the depth of said nut-engaging recess at said central plane.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 202,259 Hilton Apr. 9', 1878 796,305 Enderes Aug. 1, 1905 956,259 Amborn Apr. 26, 1910 1,261,565 Leitner Apr. 2, 1918 1,393,399 Schlehr Oct. 11, 1921 FOREIGN PATENTS Number Country Date 468,255 Germany Nov. 9*, 1928 

